Cita APA

Roy,, A. E., & Clarke,, D. (2011). Astronomy: Principles and Practice (4.). Institute of Physics.

Citación estilo Chicago

Roy,, A E., and D. Clarke. Astronomy: Principles and Practice. 4. Bristol: Institute of Physics, 2011.

Cita MLA

Roy,, A E., and D. Clarke. Astronomy: Principles and Practice. 4. Institute of Physics, 2011.